Justify it as you will, but comparing the % of player-owned fiefs vs. AI fiefs only hurts your cause. It is far easier to go to an AI fief overflowing with S&D and swipe all of it than it is to walk into (potentially hostile) player-owned territory and take their S&D away from them. In this case, having more AI-controlled fiefs helps you make money. And comparing the number of pvp and pve battles between the two regions is utterly pointless. Since you didn't bother checking, you will see that on average, NA factions are aiming to take control of larger, harder-to-capture fiefs such as the towns and castles on the map. Despite having fewer players and fewer fiefs, NA has more player-owned towns/castles than EU does. Does this make you euros more superior at strat for choosing to attack us while we are meanwhile prepping to siege castles and towns? It isn't like pve battles can't be fun. We've had some great town and castle sieges go down recently that were enjoyable from both sides, I don't think anyone in particular cared one way or the other if it was pvp or pve. Also, I don't see how taking credit for what is almost entirely panos' doing makes EU as a whole all that more appealing. He is the cause of 99% of EU's pvp battles, it isn't like you guys did much other than take AI fiefs, trade, and then "invade" the NA steppe. Pot calling the kettle black, my friend.
Either way, the reason NA is currently "behind" EU in strat, and the reason we always have been, is because we shun carebear alliances while you all flock to them time and time again. Your one invading faction from EU has 32 members, the same number as the three largest NA factions (Acre, HoC, TotRS) combined. And that is why NA strat will always remain superior to EU. We don't rely on other regions to to have our fun, we can make decently-balanced rosters and wars on our own.
Tl;dr:
If EU so busy y u invading us? Checkmate.